300 or so years is a long time in the history of any word, including “happiness” Happiness, in a modern sense, bears pretty much no relation to the happiness referred to in the Declaration of Independence. Jefferson’s use is implying a life of moral virtue. Happiness these days is definitely not about the pursuit of moral virtue. This is why, some claim, so many people are unhappy. At the heart of their unhappiness is an immorality, a selfishness, a corrupt individualism, which inevitably leaves them cold, bitter, angry, unsatisfied, and amiss. These days the pursuit of happiness is equated with the pursuit of things, of consuming, of lasciviousness, of fakery. It is the pursuit of attention, of approval, of wealth, of fame, of oneupmanship, of all the worldly things that come to nothing, bring a person to nothing more than some illusion in someone elses’ eyes. Antidepressants, opioids, benzos, alcohol, cocaine and so on, are the medical treatments for the modern pursuit of happiness, that is really the pursuit of nihilistic self-obsession dressed up as moral virtue. That is why in any survey you care to ponder, people equate wealth with moral virtue. The best antidepressant is the one which knocks out all thoughts which might open the mind to pondering the above, and what comes next. We know they are working, psychiatry is working wonders. Because the majority of people consider the status quo to be healthy, good, and virtuous.